1. Field of the Invention
This invention relates to the production of novel polyesters by the interfacial condensation of bifunctional acid halides or anhydrides with bisphenols dissolved in mixtures of alkaline hydroxides and liquid polyhydroxy hydrocarbons, ethers or amines.
2. Description of the Prior Art
Polyesters have found wide application for the production of fibers and plastic materials. Due to their technical importance, investigations are continuing for improved and more useful polyesters. Polyesters are prepared by the condensation of acid derivatives with alcohols. A high degree of polymerization has to be achieved for obtaining a useful material. To accomplish this, the alcohol and the acid molecule each has to have at least two functional groups. When the acid and the alcohol are bi-functional, then long chains can be obtained. If either component has more than two functional groups, branching or crosslinking occurs and three-dimensional networks are obtained.
Investigations on polyesters have previously been carried out wherein e.g. phthalic acid, isophthalic acid, terephthalic acid and 4,4'-benzophenone dicarboxylic acid were employed as the acid derivatives and aliphatic alcohols and phenolic compounds as the alcohols. Bisphenol-A, which is 2,2-bis[4-hydroxy-phenyl]-propane, has been of special interest as the alcohol since it can be readily prepared from acetone and phenol.
Polyesters have been modified in order to tailor specific properties for new applications. One way of modifying the properties of polyesters is to prepare copolyesters from at least two acid derivatives and/or at least two alcohols. However, it has been difficult to obtain useful copolyesters because when two or more acid derivatives or two or more alcohols are employed they have different reaction rates with the other components and generally will not produce the desired type of copolyester.
Conix in U.S. Pat. No. 3,028,364, issued Apr. 3, 1962, discloses the preparation of polyesters by condensing bisphenols with dicarboxylic acid chlorides in a two phase mixture of two liquids, the dicarboxylic acid chloride being dissolved in an organic liquid which is a solvent for the reaction product formed and the bisphenol being dissolved in a second liquid such as aqueous sodium hydroxide, which is immiscible with the first liquid. Conix discloses further that polyesters may be obtained by reacting a mixture of two or more specified bisphenols with one or more specified aromatic dicarboxylic acid chlorides or mixtures of two or more of the acid chlorides with one or more of the bisphenols.
Eareckson in Journal of Polymer Science, Volume 48, 339 (1959) discloses the polycondensation of bisphenol with acid chlorides.